Figure 1.

Age-dependent decline of anti-A/Brisbane/59/07 (H1N1) HAI titers measured at day 28 postvaccination with 2.4–3.2 µg vaccine in systemically immunized (red symbols) and skin-immunized (blue symbols) BALB/c mice presented as means with SEM on the log 2 scale. The data from this study are compiled together with previously reported titers and plotted against mouse age at time of immunization. Mouse groups: (a) mice on the RD immunized with MNPs (n = 5, ~2.3 µg HA) or IM (n = 5, 3 µg HA) replotted from²³, (b) and (e) mice on RD immunized with MNP Batch 2 (n = 8 each time point, 3.2 µg HA), (c) Mice on RD immunized with MNP Batch 1 (n = 6, 2.7 µg HA) or IM (n = 5, 2.4 µg HA), (d) Mice on WD immunized with MNP Batch 1 (n = 6, 2.7 µg HA) or IM (n = 5, 2.4 µg HA). P values calculated by 2 tailed unpaired t-test on the log₂-transformed titers are shown for the groups in which they were below 0.05. Individual antibody responses for each mouse are shown in Supplemental Fig. 3.